Authors, please do not create multiple threads for the same draft. Doing so is spammy and unfair to other writers who do not flood the forums with redundant threads. Furthermore, it helps reviewers a lot if all corresponding feedback is kept in one place for efficiency of reference and discussion.

Something that stands out to me is the size of the containment chamber. If the effective radius of this SCP is 50 meters, why isn't the chamber 55 meters in circumference? That would make it a lot safer to work with.

Something about the properties of your SCP now:

SCP-xxxx is a 1x1x2 meter cube of a highly resilient flesh-like material. The corners, floor, and ceiling of the mass are made of what appear to be human innards,

and:

The inside of SCP-xxxx appears to contain flames despite not having a source of fuel or ignition.

How do we know this?
Keep in mind that as the author, you know the entire story, but the Foundation needs to have discovered what it knows about the SCP object through observation and experimentation. You'll need to convince your reader that someone with no prior knowledge whatsoever of the anomaly managed to somehow figure out (not magically know!) all the information you've got in the article.

SCP-xxxx-3 is an anomalous being grossly resembling one of SCP-xxxx-2's worst fears.

What if SCP-XXXX-2 is afraid of heights? Or water?

After which; SCP-xxxx-2 will re-emerge no longer possessing the fear of whatever SCP-xxxx-3 embodies.

Ah, this is a nice twist. I expected the victim to be dead or mutilated or something and that would have been a cliché. This is definitely more interesting. Try to build on this; there's nothing in terms of origin story, we don't know if this thing is sentient, stuff like that. Try to answer the following questions:

Why is this monster/object here?

What does it want?

How did the Foundation find it?

Why should the reader care about it?

You don't HAVE to answer them, but at least give us what happened when the Foundation tried.